Evaluation and Improvement Strategy for Impressed Current Cathodic Protection of Nuclear Power Plant (NPP) Raw Service Water (RSW) Suction Pipeline

The raw service water (RSW) suction pipe of TQNPP was protected by both coating and impressed current cathodic protection system. Lots of bubbling were found on the outside coating, and metal base of pipe corroded in the actual operation. Design and operation of the cathodic protection system were analyzed, it was found that the energizing potential of the pipe deviated from the design value seriously, the protection circuit current was affected significantly by multiple factors, the anode cable was broken for long-term etc. Some corresponding solutions were put forward.